Emerald ash borer found in Lexington

If you live in Lexington and are considering planting a tree in your yard, don't plant an ash.

A small, bright-green insect from Asia — the emerald ash borer — has been found in Lexington, presenting people who already have ashes with a couple of unpleasant choices: Pay for expensive chemical treatments every year or two, or prepare for the trees' almost certain death.

There is a third option: If your ash tree is small, you might consider cutting your losses by taking it out now and planting something else.

On Wednesday, the Lexington Tree Board approved a resolution removing ashes from the list of approved trees that can be planted along streets and new developments, or anywhere else in the city.

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It also recommended that the local government and private property owners treat their trees with insecticides "where feasible," meaning if the tree is of historic and aesthetic value and the city or landowner can afford it. Louisville already is injecting insecticides into hundreds of ash trees in that city's Waterfront Park.

Homeowners can buy a spray to soak the ground around the trunk of their trees, but it is effective only on trees with diameters of 15 inches or less. Professionals have access to chemicals that can be injected into trees. Dave Leonard, a consulting arborist who is a member of the Lexington board, said that costs vary widely, but he estimated that the cost for a a tree with a 10-inch diameter could be $60 for a treatment that lasts a year or $120 for a two-year treatment.

The tree board also is looking for people to walk along streets and through parks looking for ash trees on public property and rights-of-way. Those trees will be marked with green ribbons.

The idea behind the ribbons is that people will know whether the tree between the sidewalk and the street in front of their house is an ash, and they'll be able to identify ashes in other public places.

No one knows how many ash trees are growing in Lexington, but a 2005 survey found that about one in 10 trees along the city's streets is an ash. Several streets are lined with ashes, said Tim Queary, the city's urban forester.

The borer has destroyed tens of millions of ashes in Michigan and tens of millions more in a dozen other states and two Canadian provinces since being discovered near Detroit in 2002.

It showed up in Kentucky in Jessamine and Shelby counties in late May, and in southern Fayette County a short time later. It now has been identified in seven Kentucky counties. Officials have placed a quarantine over a 20-county area in an attempt to slow the bug's spread.

Joe Collins, a senior nursery inspector at the University of Kentucky, said officials are trying to buy time while researching potential predators that might kill the borer, and they're looking for ash trees that have a natural resistance to the insect.

The state Department of Forestry estimates that Kentucky has 131 million white ash trees and 92 million green ashes. Most are in the "Golden Triangle" area formed by Lexington, Louisville and Cincinnati.

There are blue ashes in the area also, some of which are several hundred years old. None are known to have been infected with the borer, but officials said there is no reason to think they are immune.